1. Field of the Invention
The present invention relates to a permselective membrane. More particularly, it relates to a permselective membrane having excellent water flux and solute rejection and also excellent chemical resistance, heat resistance and compaction resistance which is easily fabricatable.
2. Description of the Prior Art
In accordance with a separation with a membrane especially a reverse osmosis, a solute in an aqueous solution can be separated without a phase change whereby a cost for energy can be small. Therefore, this is practically employed in various fields such as a desalting process for brine or sea water and a separation of an inorganic material or an organic material in a medium and also will be employed in various other fields.
It has been known as typical examples of reverse osmosis membranes, to use cellulose acetate membrane in U.S. Pat. Nos. 3,133,132 and 3,133,137 by Loeb and Sourirajan; and an aromatic polyamide membrane or a polyamide hydrazide membrane in U.S. Pat. No. 3,567,632 by Richter and Hoehu. The water fluxes and solute rejections (desalting coefficient) of these membranes have not been satisfactory. Moreover, the chemical resistances, the heat resistances, compaction resistances and fabricatabilities of the membranes have various disadvantages.